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GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear

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China Guangzhou Changfeng Steel Co., LTD certification
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GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear

GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear
GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear

Large Image :  GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear

Product Details:
Place of Origin: China
Brand Name: CF STEEL
Certification: ISO, Mill Certificate
Model Number: 40CrNiMoA, AISI4340,39CrNiMO,40NiCRMo22,SNCM439
Payment & Shipping Terms:
Minimum Order Quantity: 3MT
Price: USD800-900/MT
Packaging Details: Export Standard Packing or Customers'demand
Delivery Time: 7-15 days
Payment Terms: L/C, T/T
Supply Ability: 1000t/Month
Detailed Product Description
Standard: AISI,DIN,ASTM,GB Surface: Machined,black,Plain,mill Finish Or Peeled Finish,Grinding
Technique: Forged,Hot Rolled,Hot Work Mould Steel Test: SGS / Ut 100% / Element Testing
Delivery Condition: Hot Rolled, Forged Ut Standard: Sep 1921-84 Class 3 C/C To D/D
Sample: Free Heat Treatment: Annealing/Q+T
Hs Code: 722540 & 722830
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China Forging Steel Bars 4340 Steel | 36CrNiMo4 | 1.6511 | EN24 | SNCM439

1.36CrNiMo4 AISI 4340 forged steel bar sizes we can offer;
Round bar: 200-1000mm
Square bar:150×150-600×600mm

2.Supply condition for 36CrNiMo4 AISI 4340 Forged steel bars:Black /Rough Machined /Rough turned

3.36CrNiMo4 AISI 4340 Forged Steel round bar tolerance:
Black surface
Forged sizes up to 500mm (-0/+5mm)
Forged sizes above 500mm in diameter (-0/+8mm)
Machined surface to all sizes (-0/+3mm)

4.Futhur heat treatment for 36CrNiMo4 AISI 4340 forged steel :

5.36CrNiMo4 AISI 4340 Steel Equivalent
Country USA Britain Britain Japan
Standard ASTM A29 EN 10250 BS 970 JIS G4103
Grades 4340 36CrNiMo4/ EN24/817M40 SNCM 439/SNCM8

6.36CrNiMo4 AISI 4340 Forged steel chemical composition
C% Carbon 0.38 - 0.43
Mn% Manganese 0.6 - 0.8 max
P% Phosphorus 0.035 max
S% Sulfur 0.040 max
Si% Silicon 0.15 - 0.3
Ni% Nickel 1.65 - 2.0
Cr% Chromium 0.7 - 0.9
Mo% Molybdenum 0.2 - 0.3

7.36CrNiMo4 AISI 4340 Forged steel Application
AISI 4340 steel is used in most industry sectors for applications requiring higher tensile/yield strength than 4140 steel can provide.
Some typical applications such as:

Aircraft Landing Gear
Oil and Gas Drilling,
Warm and Cold Forming,
Machine Building,
Transfer Systems, like power transmission gears and shafts.
General engineering industries and structural use applications, such as: heavy duty shafts, gears, axles, spindles, couplings, pins, chucks, molds etc.

8.Quality control:
1. Melting Process: EAF/BOF+LF+VD resulting in ingots
2. Both ends cut by saw
3. Ratio of forging:minimum 3:1
4. Grain size of final product: according to ASTM E112 more than 5,preferred more than 8
5. Ultrasonic test: As per SEP1921 Class C/c or D/d

9.Heat treatment of 36CrNiMo4 AISI 4340Steel

Heat treatment after forging is carried out to render the steel suitable for machining, and to meet the mechanical property limits specified for the steel's particular applications. There are several ways to heat treat a given steel part and it is only through practice that the optimum temperature and conditions may be defined. The following information should be taken as a guide only.

To obtain a pearlitic structure on certain parts for machining, 4340 should be annealed at a nominal temperature of 1525 º F (830 º C,) cooling to 1350 º F (730 º C) and furnace cooling to 1130 º F (610 º C) at a rate of 20 º F (11 º C) per hour, then air cooling. This process, known as full annealing, is very time consuming as it involves slow cooling over the entire temperature range from the austenitizing temperature to a temperature well below that at which transformation is complete.

To obtain a spheroidized structure in 4340 grade involves austenitizing at 1380 º F (750 º C,) furnace cooling to 1300 º F (705 º C) then to 1050 º F (565 º C) at a rate of 5 º F (3 º C) per hour. This structure will probably result in better machinability than will the coarse lamellar pearlite structure obtained by the full anneal process.

This process is defined as heating a steel to a temperature above the ferrite to austenite transformation temperature, then cooling in air to a temperature well below this transformation temperature. The treatment may be carried out on forged products as a conditioning treatment prior to final heat treatment. Normalizing also serves to refine the structure of forgings that might have cooled non-uniformly from their forging operation. The nominal normalizing temperature for 4340 grade is 1500 º F (815 º C,) but production experience may necessitate a temperature either 50 º F (10 º C) above or below this temperature. . As a rule of thumb, when forgings are normalized before, say, carburizing or hardening and tempering, the upper range of normalizing temperatures is used. When normalizing is the final heat treatment, the lower temperature range is used.

This heat treatment results in the formation of martensite after quenching, resulting in increased hardness and tensile strength. A temperature range of 1500 - 1550 º F (815 - 845 º C) is the normal austenitizing temperature for direct hardening of 4340 grade. Oil quenching is normally used for 4340 as the alloy's hardenability is suited to this quenching method.

Tempering is carried out to relieve stresses from the hardening process, but primarily to obtain mechanical properties required for the final application. The actual tempering temperature will be chosen to meet the required properties, and in many cases will be a matter of trial and error.

10.MOQ: one piece per size/grade

11.Payment term: FOB CIF CFR EXW and so on

12.Delivery time : 7 to 30 days after deposit received.

GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear 0
GB 4340 Steel Bar 36CrNiMo4 1.6511 EN24 SNCM439 For Aircraft Landing Gear 1
Changfeng Tool & Die Steel main product:
STANDARD/GRADE of steel Flat Bar Size(mm) Round bar Size(mm) Technics
DIN AISM JIS GB(China) Thickness Width Length Diameter Length
1.121 SAE1050 S50C 50# 10-450 155-2200 2000-12000     Forged, Hot Rolled
1.2311 P20 PDS-3 3Cr2Mo 10-460 155-2200 2000-10000 20-200 2000-6000
1.2738 P20+Ni - 3Cr2NiMnMo 21-300 155-2200 2000-8000 20-200 2000-6000
1.2379 D2 SKD10 SKD10 10-200 155-810 2000-6000 14-80 3000-6000
1.2080 D3 SKD1 3Cr2Mo 10-200 155-810 2000-6000 20-200 3000-6000
1.2083 420 - 4Cr13 10-500 155-1200 2000-6000 12-300 3000-6000
1.2344 H13 SKD61 4Cr5MoSiV1 10-500 155-1600 2000-6000 16-400 3000-6000
1.2510 O1 SKS3 9CrWMn 10-200 155-810 2000-6000 20-200 3000-6000
1.7225 SAE4140 SCM440 42CrMo 10-280 155-2200 2000-6000 16-450 3000-6000


About Us
Guangzhou Changfeng Steel Co., Ltd.
is a professional special steel company, which specializing in this line in China since 2005. Our main products are Plastic Mould Steel, Hot Work Mould Steel, Cold Work Mould Steel, Alloy Structural Steel, Tool Steel, Stainless Steel, Carbon Steel and Forged Block.


To ensure provide high quality products to customers, we have close cooperation with many Chinese first class special steel enterprises, including Baosteel Group, Dongbei Special Steel, Changcheng Special Steel, Hongsheng Heavy Industry, Xingcheng Special Steel and Daye Special Steel.



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Guangzhou Changfeng Steel Co., LTD

Contact Person: Echo

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